Friday mystery object #304

This week I was worried that I didn’t have a mystery object planned, but then I stumbled across this on my phone:

mystery304

 

It’s probably a bit too easy for some of you, so I’d encourage using some cryptic clues and hints to say what it is in the comments box below.

I’ve had a problem with spam comments recently and have switched on a filter to ensure that people’s first posts are approved (regular posters shouldn’t be affected) – fear not, I will be keeping an eye on it and approving first timers!

Have fun!

Friday mystery object #255 answer

Last Friday I gave you this rather interesting looking object to identify, preferably using a rhyme:

wpid-img_20150626_095757-1_20150626095918070.jpg

Believe it or not the photographs show either side of the same object – on one side it just looks like a rugose lump and on the other it shows a rather nice natural spiral.

Aside from some great humorous comments by 4utu and Henrik Nielsen, there were some of you who worked out that this is the operculum from a marine snail and even managed to explain that in rhyme – so very well done to Barbara, Chris and especially Lee Post who upped the ante by writing a full verse:

oh purr Q lum from foreign shores
possibly from a near ites door
side door -back door does not exist
main door -strong door , built to resist

Flick Baker went a step further (taxonomically) by identifying that this operculum is from a snail in the genus Turbo with the rhyme: “Gives your engine serious puff, even when she’s running rough“.

Green Turban Shell (Turbo marmoratus) showing aperture closed by the operculum

Green Turban Shell (Turbo marmoratus) showing aperture closed by the operculum

More specifically, this operculum is from the South African Turban Shell Turbo sarmaticus Linnaeus, 1758.

The operculum is a part of many snails that is often forgotten about – it forms a protective trapdoor that the snail closes behind itself when it retreats inside its shell (‘operculum’ means ‘cover’ or ‘lid’ in Latin). This trapdoor helps prevent desiccation in land snails and helps protect against predators in marine snails.

When the animal dies the operculum will often fall off as the body of the animal decays or is eaten, so often it won’t find its way into a museum collection with the rest of the shell. However, opercula can be quite distinctive and are sometimes more useful for identifying a species than the rest of the shell – a handy point to remember.

Friday mystery object #200 answer

Last week I gave you this object to identify:

mystery200

It was a bit of a mean one, since it had no scale bar and the specimen is quite old and dried out, so it doesn’t look much like the living animal.

I had hoped that this would mean that nobody would manage to identify it, but I wasn’t at all surprised when correct suggestions started coming in.

Dave Hone was the first to get the correct kind of animal, although he was a bit thrown by the outer surface – vannabarber was also on the right track, but thrown by the texture. In fact the texture led to some interesting suggestions, including pumice, fossil, bezoar and Pompeian pinecone.

In the end, henstridgesj made the right connection and identified the species, with Anna Pike, rachel and Crispin Wiles all coming to the same conclusion. This is the dried and shrivelled remnant of a Gumboot (or Giant Western Fiery) Chiton Cryptochiton stelleri (Middendorff, 1847). Also known as the ‘Wandering Meatloaf’ for obvious reasons!

Cryptochiton stelleri (Gum Boot Chiton) by Jerry Kirkhart

Chitons are an ancient class of mollusc called the Polyplacophora – a name that means “bearing many (or several) tablets (or plates)”. They get this name from the eight plates (also known as valves) that they have on their backs.

Most chitons have these valves visible (see below), but the huge Gumboot Chiton has the valves hidden underneath their rubbery girdle.

Tonicella lineata

Tonicella lineata showing the eight valves characteristic of chitons

Chitons are remarkably conservative animals, having changed little since the group arose around half a billion years ago. They have few predators and manage to live a blameless and slow-paced life feeding on algae and detritus on rocks in the world’s oceans, that they rasp off with a fairly simple rasping radula.

There are few ways of spending time on the sea shore that are more enjoyable than turning over rocks in the quest for chitons. Except maybe finding washed-up bones. Or maybe finding both together!

chiton-bone

Friday mystery object #199 answer

On Friday I gave you this rather beautiful object to identify,which came to light during our mollusc Bioblitz last week:

mystery199

It turns out that it didn’t prove much of a challenge and was identified to species level in no time. So well done to Kevin, Anna Pike, @benharvey1 and Carlos Grau!

In fact, Carlos went a step further than identifying the specimen and told the very story I was planning to tell in this post. It’s great to hear stories like this about specimens or species, so I’ll share it with you in Carlos’ words:

This picture immediately brought back memories of my old seashell-collecting guide I had when I was about 12 and haven’t looked at for years and years (I will look for it next time I’m at my parent’s). The book said that this species was considered so valuable that fakes were made in rice paste by Chinese artisans, and that the counterfeits are now more rare and valuable than the actual shell! I remember finding that bit of information amazing.

It’s been so long I had to Google the book, it’s “Guide to Seashells of the World” by R. Tucker Abbott.

The animal is… Continue reading